Patent GB-836151-A (GB)
Title: Improvements in or relating to photographic reproduction
IPC: C07D215/38
Filed: 1957-07-03
Abstract: A composition for use on a support in electrophotography comprises a solution of a natural resin (which may be modified) together with an azomethine of the formula R2.CH:NR1 or NC.CR4:NR3, where R1 and R2 are aromatic radicals (carboxylic or heterocyclic), R3 is aminophenyl (optionally N-substituted) and R4 is aryl, aroyl, cyano or carbalkoxy, with or without a sensitizing dyestuff.  Specified resins are Manila copal, colophony esterified or modified with formaldehyde, zinc resinate, and polymerized (e.g. dimerized) or hydrated natural resins.  Suitable azomethines and sensitizing dyestuffs are listed. Specifications 633,747 and 633,796 are referred to.ALSO:Azomethines of the formula R1-N = CH-R2 are made by condensing R1-NH2 with R2-CHO, the groups R being aromatic radicals (carbocyclic or heterocyclic), especially p-dimethylaminophenyl.  R1 may also be naphthyl or o- or p-methoxyphenyl and R2 may be naphthyl or o- or p-nitrophenyl.  Examples are given of the preparation of a number of azomethines using as reactants the following: benzaldehyde, o - and p - nitrobenzaldehyde, p - dimethylaminobenzaldehyde, 2 - nitro - 4cyanobenzaldehyde, p - methoxybenzaldehyde, 2:4 - dihydroxybenzaldehyde, diphenyl - 4aldehyde, x - naphthaldehyde, anthracene - 9aldehyde, furfural and thiophene - 2 - aldehyde; aniline, 3:5-dimethylaniline, o- and mchloranilines, p - bromaniline, p - nitraniline, p - anisidine, 2 - methyl - 4 - nitraniline, pphenylenediamine (which gives a bis-compound), N:N - dimethyl - p - phenylenediamine, a  - and b  - naphthylamines, 5 - amino - acenaphthene, 3 - aminopyridine, 6 - aminoquinoline and 6aminocarbazole. p-Aminobenzylidene-p-anisidine is made by reduction of the corresponding nitro compound.  Azomethines of the formula R3-N = CR4-CN are made by condensing R3-NO with R4-CH2-CN R3 being an aminophenyl group (which may be substituted) and R4 being aryl, aroyl, cyano or carbalkoxy.  In the examples products are made from p-nitroso-dimethylaniline and benzyl cyanide, p-nitrobenzyl cyanide, benzoyl-acetonitrile, malonic dinitrile and ethyl cyanacetate. A further azomethine is obtained by condensing p-nitroso-dimethylaniline with 2-nitro4-cyano-toluene. Specifications 633,747 and 633,796 are referred to.ALSO:Azomethines of the formula R1-N = CH-R2 are made by condensing R1-NH2 with R2-CHO, where R1 may be p-dimethylaminophenyl, p - methoxyphenyl b  - naphthyl, 3-pyridyl or 6-quinolyl, and R2 may be p-aminophenyl, p - dimethylaminophenyl, p - nitrophenyl or 2 : 4 - dihydroxyphenyl.  A bis-compound is made from p-phenylene diamine and p-dimethylaminobenzaldehyde.  Azomethines of the formula R3-N = CR4-CN are made by condensing R3-NO with R4-CH2-CN, R3 being an aminophenyl group (especially p-dimethylaminophenyl) and R4 cyano, carbalkoxy, phenyl, p-nitrophenyl or benzoyl.  A further azomethine is obtained by condensing p - nitroso - dimethylaniline with 2-nitro-4-cyano-toluene.  Specifications 633,747 and 663,796 are referred to.ALSO:A composition for use on a support in electrophotography comprises a synthetic resin together with an azomethine of the formula R2.CH:NR1 or NC-CR4:NR3, where R1 and R2 are aromatic radicals (carbocyclic or heterocyclic), R3 is aminophenyl (optionally N-substituted) and R4 is aryl, aroyl, cyano or carbalkoxy, with or without a sensitizing dyestuff.  Examples are given of compositions containing the following resins: coumarone resin-modified maleic acid and ketone-aldehyde.  Other types of resins mentioned are phenolic (especially phenol-formaldehyde, which may be modified with colophony); indene, polyvinyl chloride, acetate, acetals, alcohol and ethers; polyacrylic and methacrylic esters; polystyrene and isobutylene; phthalates; alkyds; maleic acid resins; colophony esters of mixed higher alcohols; urea- and melamine-formaldehyde, xylene-formaldehyde; polyamides and polyurethanes; aldehyde resins; ketone resins.  Suitable azomethines and sensitizing dyestuffs are listed.  Specifications 633,747 and 633,796 are referred to.